Heat sink core member and its fabrication procedure

ABSTRACT

A heat sink core member made by: preparing a predetermined mass of aluminum block, extruding the aluminum block through an extruding machine into a tubular body having one close end wall and then punch-cutting the outside wall of the tubular body to form a plurality of densely distributed and equally spaced vertical retaining grooves. Radiation fins can easily be affixed to the vertical retaining grooves of the tubular body to form a heat sink.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to heat sink fabrication technology and more particularly to a method of making a heat sink core member by extruding a predetermined mass of aluminum block into a tubular body having one close end wall and then punch-cutting the outside wall of the tubular body to form a plurality of densely distributed and equally spaced vertical retaining grooves for easy mounting of radiation fins.

(b) Description of the Prior Art

A radiation fin type heat sink generally comprises a tubular core member and a plurality of radiation fins. The radiation fins are radially spaced around the periphery of the tubular core member. Because the radiation fins are integrally formed with the periphery of the tubular core member, the fabrication of the heat sink is complicated, and the cost is high. Further, due to technical limitation, the radiation fins have a thick wall thickness. In consequence, the heat sink is heavy. Due to a limited number of radiation fins, the heat dissipation efficiency of this kind of heat sink is limited.

During application, the tubular core member is attached with its one end to the heat source (CPU or LED device). A heat pipe may be attached to enhance heat dissipation performance. Further, the tubular core member may be made in the shape of a round tube, rectangular tube or polygonal tube.

There are known heat sinks in which the radiation fins are soldered to the periphery of the tubular core member. However, it takes much time and labor to solder every radiation fin to the periphery of the tubular core member. Before soldering, an electroplating technique may be necessary so that different metal materials can be soldered together. Further, this fabrication procedure is not environmentally friendly. Further, solder-bonding will lower heat transfer efficiency. Further, a heat sink may be directly cut from a solid aluminum block. This method wastes much labor and time and will produce many waste materials, increasing the cost considerably.

Further, a heat sink core member may be directly extruded from an aluminum ingot. This method is to extrude an aluminum ingot into a tubular member having longitudinal grooves spaced around the periphery. The tubular member is than cut into tubular core members subject to the desired length. Radiation fins are than fastened to the longitudinal grooves of each tubular core member. This fabrication procedure still has drawbacks as follows:

-   -   1. Due to technical limitations, the number of the longitudinal         grooves of the extruded heat sink core member is limited, and         therefore only a limited number of radiation fins can be         fastened to the periphery of the heat sink core member. When the         number of the longitudinal grooves is increased, the wall         structure of the heat sink core member under extrusion may be         damaged.     -   2. The finished heat sink core member is a hollow tubular member         having two open ends. A plate member must be bonded to the heat         sink core member to close its one end so that the blocked end of         the heat sink core member can be attached to the heat source or         used to support an attached member during application. However,         because the plate member and the heat sink core member are not         made integrally, a capillary effect will occur, lowering the         heat transfer performance.

Therefore, it is desirable to provide a heat sink core member and its fabrication procedure that eliminates the drawbacks of the prior art designs and techniques.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is one object of the present invention to provide a heat sink core member fabrication procedure for making a heat sink core member by means of preparing a predetermined mass of aluminum block, and then extruding the aluminum block through an extruding machine into a tubular body having one close end wall and then punch-cutting the outside wall of the tubular body to form a plurality of densely distributed and equally spaced vertical retaining grooves. Thus, radiation fins can easily be affixed to the vertical retaining grooves of the tubular body to form a high-performance heat sink.

Using the heat sink core member fabrication procedure for making a heat sink core member of this application, the finished heat sink core member has a close end wall. As a result, the invention prevents a capillary effect, thus effectively facilitating heat transfer.

In the heat sink core member fabrication procedure for making a heat sink core member of the present application, the punch-cutting step may include three substeps, i.e., the coarse punch-cutting substep to punch-cut the outside wall of said tubular body into a predetermined number of rough grooves, the fine punch-cutting substep to punch-cut each said rough groove into a fine groove, and the superfine punch-cutting substep to punch-cut each said fine groove. These substeps are performed automatically for facilitating the fabrication and saving the fabrication time and labor.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a heat sink core member fabrication procedure in accordance with the present invention.

FIG. 2 is an alternate form of the heat sink core member fabrication procedure in accordance with the present invention.

FIG. 3 illustrates a circular aluminum block prepared according to the present invention.

FIG. 4 illustrates a rectangular aluminum block prepared according to the present invention.

FIG. 5 illustrates a round tubular body extruded according to the present invention.

FIG. 6 is a sectional view of FIG. 5.

FIG. 7 is a top view of FIG. 5.

FIG. 8 illustrates a rectangular tubular body extruded according to the present invention.

FIG. 9 is a sectional view of FIG. 8.

FIG. 10 is a top view of FIG. 8.

FIG. 11 is an oblique elevation of a round tube-like heat sink core member prepared according to the present invention.

FIG. 12 is a sectional view of FIG. 11.

FIG. 13 is a top view of FIG. 11.

FIG. 14 is an oblique elevation of a rectangular tube-like heat sink core member prepared according to the present invention.

FIG. 15 is a sectional view of FIG. 14.

FIG. 16 is a top view of FIG. 14.

FIG. 17 is a schematic sectional view, illustrating radiation fins inserted to the respective vertical retaining grooves of a round tube-like heat sink core member according to the present invention.

FIG. 18 corresponds to FIG. 17, illustrating the radiation fins affixed to the respective vertical retaining grooves.

FIG. 19 is an oblique elevation of a heat sink based on a round tube-like heat sink core member according to the present invention.

FIG. 20 is an oblique elevation of a heat sink based on a rectangular tube-like heat sink core member according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As described in FIG. 1, a predetermined mass of aluminum block 1 (see FIG. 3 or FIG. 4) is extruded through an extruding machine into a tubular body 10 having one close end wall 11 (see FIGS. 5˜7 or FIGS. 8˜10), and then the outside wall of the tubular body 10 is punch-cut to form a plurality of vertical retaining grooves 12 that are equally spaced around the periphery in a densely distributed manner (see FIGS. 11˜13 or FIGS. 14˜16), and thus a heat sink core member 100 is obtained. Radiation fins 200 can then be fastened to the retaining grooves 12 of the heat sink core member 100 (see FIG. 17 or FIG. 18) to form a heat sink 300 (see FIG. 19 or FIG. 20).

The heat sink core member fabrication procedure includes the steps of:

-   -   (1) preparing a predetermined mass of aluminum block 1;     -   (2) extruding the aluminum block 1 through an extruding machine         into a tubular body 10 having one close end wall 11; and     -   (3) punch-cutting the outside wall of the tubular body 10 to         form a plurality of densely distributed and equally spaced         vertical retaining grooves 12.

As described in FIG. 2, the step of punch-cutting the outside wall of the tubular body 10 includes the substeps of coarse punch-cutting, fine punch-cutting and superfine punch-cutting. The coarse punch-cutting substep is to punch-cut the outside wall of the tubular body 10 into a predetermined number of rough grooves. The fine punch-cutting substep is to punch-cut each rough groove into a fine groove substantially close to the predetermined size. The superfine punch-cutting substep is to punch-cut each fine groove again, modifying the size of each fine groove into one respective finished vertical retaining groove 12. By means of performing one coarse punch-cutting substep, at least one fine punch-cutting substep and at least one superfine punch-cutting substep, the outside wall of the tubular body 10 is rapidly and efficiently processed to form the desired, densely distributed and equally spaced vertical retaining grooves 12. These substeps are performed automatically for facilitating the fabrication and saving much the fabrication time and labor.

Further, during the extrusion step, vertical ribs 13 are formed on the inside wall of the tubular body 10 (see FIGS. 5˜7 or FIGS. 8˜10). Further, a hole-drilling step may be performed to make a mounting hole 14 on each vertical rib 13 (see FIG. 11 or FIG. 14), for mounting of an attached member. One or more mounting holes may be formed in the close end wall 11 of the tubular body 10 for the mounting of an attached member.

Further, the tubular body 10 can be made in any of a variety of shapes and dimensions. For example, the tubular body 10 can be shaped like a round tube as shown in FIGS. 5˜7. Alternatively, the tubular body 10 can be shaped like a rectangular tube as shown in FIGS. 8˜10.

Further, the radiation fins 200 to be fastened to the tubular body 10 can be made in any of a variety of shapes and sizes. However, the radiation fins 200 must be configured for press-fitting into or riveting to the vertical retaining grooves 12.

Further, the vertical retaining grooves 12 may be variously configured. Preferably, the outside wall of the tubular body 10 is so punch-cut that a first protruding portion 121 and a second protruding portion 122 are formed and disposed along two opposite lateral sides of each vertical retaining groove 12. After one radiation fin 200 is inserted into one vertical retaining groove 12, the adjacent first protruding portion 121 is deformed in the direction toward the adjacent second protruding portion 121 to have the radiation fin 200 be firmly seized in between the first protruding portion 121 and the second protruding portion 122 (see FIG. 18).

Although particular embodiments of the invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the invention. Accordingly, the invention is not to be limited except as by the appended claims. 

What is claimed is:
 1. A heat sink core member fabrication procedure, comprising the steps of: (a) preparing a predetermined mass of aluminum block; (b) extruding said aluminum block through an extruding machine into a tubular body having one close end wall; and (c) punch-cutting the outside wall of said tubular body to form a plurality of densely distributed and equally spaced vertical retaining grooves.
 2. The heat sink core member fabrication procedure as claimed in claim 1, wherein said step (c) comprises a coarse punch-cutting substep to punch-cut the outside wall of said tubular body into a predetermined number of rough grooves, a fine punch-cutting substep to punch-cut each said rough groove into a fine groove, and a superfine punch-cutting substep to punch-cut each said fine groove.
 3. The heat sink core member fabrication procedure as claimed in claim 1, wherein said step (b) extrudes said aluminum block through an extruding machine into a tubular body having one close end wall and a plurality of vertical ribs on the inside wall thereof.
 4. The heat sink core member fabrication procedure as claimed in claim 3, further comprising a substep of making a plurality of mounting holes on said vertical ribs after said step (b) and before said step (c).
 5. The heat sink core member fabrication procedure as claimed in claim 1, further comprising a substep of making a plurality of mounting holes on said close end wall of said tubular body after said step (b) and before said step (c).
 6. The heat sink core member fabrication procedure as claimed in claim 1, wherein said tubular body is in a shape of a round tube.
 7. The heat sink core member fabrication procedure as claimed in claim 1, wherein said tubular body is in a shape of a rectangular tube.
 8. A heat sink core member comprising a tubular body, a close end wall located on one end of said tubular body, and a plurality of vertical retaining grooves equally spaced around the periphery of said tubular body for the mounting of one radiation fin in each said vertical retaining groove.
 9. The heat sink core member as claimed in claim 8, wherein said tubular body comprises a plurality of first protruding portions and a plurality of second protruding portions respectively extending along said vertical retaining grooves at two opposite sides.
 10. The heat sink core member as claimed in claim 8, further comprising a plurality of vertical ribs axially formed on an inside wall of said tubular body and a mounting hole located on one end of each said vertical rib.
 11. The heat sink core member as claimed in claim 8, further comprising a plurality of mounting holes located on said close end wall.
 12. The heat sink core member as claimed in claim 8, wherein said tubular body is in a shape of a round tube.
 13. The heat sink core member as claimed in claim 8, wherein said tubular body is in a shape of a rectangular tube. 